S1+M2 TRANSDUCERS: Easy to setup the transducers on the pipe and enter the required information in the control unit.No need to destroy the pipeline and stop production during the measurement process.S1(DN15-100mm, 1/2-4"), M2(DN50-700mm, 2-28").DIGITAL DISPLAY: The Ultrasonic Flowmeter can display cumulative flow, instantaneous flow, velocity, and working status at the same time. Accuracy: 1%, linearity: 0.50%, repeatability: 0.20% accuracy: ±1%, calibration certs included. Note: In order to provide a better user experience, we upgraded the product label. The product you received may be the old version or the new version.DATA STORAGE AND OUTPUT: This Ultrasonic Flow Meter has a built-in data logger, which can store up to 2000 lines of measurement data. And you can download the logged data onto PC through the RS232 interface..LONG STAND TIME: This Flow Meter is equipped with a built-in high-capacity rechargeable battery, which can support the flowmeter to work continuously for up to 12 hours..WIDE APPLICATION: Come with S1+M2 transducers, and the measuring range is DN15-700mm, 1/2-28". It can work on Copper pipe, PVC pipe to detect the flow of liquids such as sea water, alcohol, river water, industrial sewage, lubricating oil, diesel, fuel oil, etc.Not suitable for rubber pipe, SAE30 hydraulic fluid.